Electrical Wiring; Low Voltage Wiring; Line Voltage Wiring; Grounding - Nordyne M4RC Upflow Installation Instructions Manual

ELECTRICAL WIRING

WARNING:
To avoid electric shock, personal injury, or death,
turn off the electric power at the disconnect
or the main service panel before making any
electrical connections.
• Electrical connections must be in compliance with all
applicable local codes with the current revision of the
National Electric Code (ANSI/NFPA 70).
• For Canadian installations the electrical connections
and grounding shall comply with the current Canadian
Electrical Code (CSA C22.1 and/or local codes).
IMPORTANT NOTE: If replacing any of the original
wires supplied with the furnace, the replacement wire
must be copper wiring and have a temperature rating
of at least 105°F (40°C). For electrical specifi cations,
refer to the furnace nameplate or Table 6 (page 30).

Low Voltage Wiring

The thermostat must be installed according to the
instructions supplied by the thermostat manufacturer.
Low voltage connections (24 VAC) from the thermostat
are wired to the terminal strip on the integrated control in
the furnace. Figure 37 contains the proper connections
for heating only (two-wire) and heating/cooling (four-wire)
applications. Recommended minimum wire gauge for
thermostat wiring is shown in Table 6.
The thermostat must not be installed on an outside wall or
any other location where its operation may be adversely
affected by radiant heat from fi replaces, sunlight, or lighting
fi xtures, and convective heat from warm air registers or
electrical appliances.
A/C CONDENSING UNIT
3 AMP
ROOM
FUSE
THERMOSTAT
R
Connect
C
R & W
Y
For Heating
G
Only
W
9 6 3
NOTE: The "Y" terminal 8 5
4 1
7
on the control board
must be connected to the
thermostat for proper
6 3
2
cooling mode operation. 5
4 1
FIELD WIRING
LOW VOLTAGE
CONNECTION
NEUTRAL LEADS
Figure 37. Low Voltage Field, Four-wire
Heating / Cooling Applications
CONDENSING UNIT
CONTROL BOX
EXPANSION PORT
(MOTOR CONNECTION)
SPEED
SELECT
STATUS
RED
GREEN
FLAME
YELLOW
180
BLOWER
2 120
OFF
90
DELAY
60
MOTOR SPEED TAPS
(NOT USED)
ELECTRONIC AIR CLEANER
HUMIDIFIER TAP
IMPORTANT NOTE: Set the heat anticipator according
to the instructions supplied by the thermostat
manufacturer.
To determine the heat anticipator setting:
1. Add the current draw of the system components; or
2. Measure the current fl ow on the thermostat R-W circuit
after the circulating blower motor has started.
The six pin terminal marked "Expansion Port" is not used
in the single stage furnace as shipped from the factory. It
is used for the furnace control board to communicate to
a fi xed speed or variable speed high effi ciency motor that
may be optionally installed. Please contact your distributor
for the proper upgrade motor kit.

Line Voltage Wiring

It is recommended that the line voltage (115 VAC) to
the furnace be supplied from a dedicated branch circuit
containing the correct fuse or circuit breaker for the furnace
as listed in Table 6.
IMPORTANT NOTE: An electrical disconnect must be
installed readily accessible from and located within
sight of the furnace. See Figure 38 (page 30) or the
wiring diagram label inside of the control door. Any
other wiring methods must be acceptable to authority
having jurisdiction.
CAUTION:
Label all wires prior to disconnection when
servicing controls. Wiring errors can cause
improper and dangerous operation. Verify
proper operation after servicing.
IMPORTANT NOTE: Proper line voltage polarity must
be maintained in order for the control system to
operate correctly. Verify the incoming neutral line is
connected to the white wire and the incoming "hot"
line is connected to the black wire. The furnace will not
operate unless the polarity and ground are properly
connected as shown in Figure 38.

Grounding

WARNING:
To minimize personal injury, the furnace cabinet
must have an uninterrupted or unbroken electrical
ground. The controls used in this furnace require
an earth ground to operate properly. Acceptable
methods include electrical wire or conduit
approved for ground service. Do not use gas
piping as an electrical ground!
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